As many people have quite a hard time syncing their wallets to even get started with Ethereum I offer my chaindata folder as a regular dump (.tar.gz). Downloading a dump is in most cases way faster than syncing from scratch. I have heard of people waiting for a sync for two weeks straight.

Is this secure for me or do I expose secrets of my wallet doing this / do I risk being hacked?

(This should not be a debate about if you can trust my or other peoples chaindata dump.)

After downloading make sure to check the sha256 sum, stop geth / Ethereum wallet and replace your chaindata folder with the one from my archive. After that start geth / your Ethereum wallet again and let it sync the remaining blocks. This should be a lot faster than a clean sync.

(Please make a backup of your private keys first in case you delete something that's wrong!)

Who am I?

Just some German guy that wants to help people out by hosting current copies of the chain on a German server.

Hi there. Is it your server? If so, you've just advertised its existence to the world on a public forum :-) Regardless of whether your keys are safe while other people are downloading the chaindata, have you performed any sort of general security audit? :-)
– Richard HorrocksJul 10 '17 at 18:20

Yes this is my server. Exposing its existence to the world is not harming anything as all public IP ranges are scanned 24/7/365 anyways ;) The server is secured following securities best practices and 5 years of experience. I cannot go deeper into what has exactly been done to secure things. I hope you can understand. EDIT: It is also audited 24/7 of course.
– FlatronJul 10 '17 at 21:35

Yeah that's up to them. Like anywhere in the world 50/50 if you are thrown over or if you can trust a person. Thanks for the answer. The trust questions is aside the point. I was just curious if there is anything in there linking to me or exposing my data in any way.
– FlatronJul 8 '17 at 20:39

Nothing not already exposed on the blockchain. Your secrets are in the keystore folder. Chaindata is common to all users following the same chain.
– Rob Hitchens - B9labJul 16 '17 at 20:54

The blockchain data are just a record of all the transactions done in the ethereum blockchain. So the geth export command (that just export the blockchain data) don't export your private key whatsoever. So don't worry about your wallet security.

It's a nice idea to take the chaindata folder of the trustworthy person to make your geth client synchronize faster, you just have to be sure it's the right ethereum blockchain.

I directly upload the chaindata folder because even geth export is fast geth import takes equally long than downloading it directly. While extracting the complete folder is way faster.
– FlatronJul 9 '17 at 20:52